content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.observable.internal.operators;
  
  import static org.junit.Assert.assertEquals;
  
  import java.util.concurrent.Callable;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.junit.Test;
  
  import io.reactivex.observable.Completable;
  
  public class CompletableFromCallableTest {
      @Test(expected = NullPointerException.class)
      public void fromCallableNull() {
          Completable.fromCallable(null);
      }
  
      @Test
      public void fromCallable() {
          final AtomicInteger atomicInteger = new AtomicInteger();
  
          Completable.fromCallable(new Callable<Object>() {
              @Override
              public Object call() throws Exception {
                  atomicInteger.incrementAndGet();
                  return null;
              }
          })
              .test()
              .assertResult();
  
          assertEquals(1, atomicInteger.get());
      }
  
      @Test
      public void fromCallableTwice() {
          final AtomicInteger atomicInteger = new AtomicInteger();
  
          Callable<Object> callable = new Callable<Object>() {
              @Override
              public Object call() throws Exception {
                  atomicInteger.incrementAndGet();
                  return null;
              }
          };
  
          Completable.fromCallable(callable)
              .test()
              .assertResult();
  
          assertEquals(1, atomicInteger.get());
  
          Completable.fromCallable(callable)
              .test()
              .assertResult();
  
          assertEquals(2, atomicInteger.get());
      }
  
      @Test
      public void fromCallableInvokesLazy() {
          final AtomicInteger atomicInteger = new AtomicInteger();
  
          Completable completable = Completable.fromCallable(new Callable<Object>() {
              @Override
              public Object call() throws Exception {
                  atomicInteger.incrementAndGet();
                  return null;
              }
          });
  
          assertEquals(0, atomicInteger.get());
  
          completable
              .test()
              .assertResult();
  
          assertEquals(1, atomicInteger.get());
      }
  
      @Test
      public void fromCallableThrows() {
          Completable.fromCallable(new Callable<Object>() {
              @Override
              public Object call() throws Exception {
                  throw new UnsupportedOperationException();
              }
          })
              .test()
              .assertFailure(UnsupportedOperationException.class);
      }
  }
  